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Marvin Epperson
Director of Technical Services
PH 317-852-0630 
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To order a NTPA rulebook, order online, call the NTPA office at 614-436-1761 or mail $6 plus $2 shipping and handling to WPI/NTPA, 6155-B Huntley Rd. Columbus, OH 43229.


Attention Competitors

Effective Immediately, 11/14/2022, the current version of the Mitas 24.5 x 32 does not meet the specifications in the NTPA Rulebook, therefore they will not be legal for competition in the 2023 pulling season. Until a new version is presented for approval to the WPI Executive Board and NTPA Technical Services, this ruling is in effect with no exceptions.


Please be advised that the Mitas 24.5 x 32 and any 18.4 x 16.1 tires are under review. Their legality is currently being investigated, and an announcement of this decision is expected shortly.


Also a reminder that it’s the competitors responsibility when buying products for their pulling vehicle, to make sure it’s legal for NTPA competition.


New Rules for the NTPA 2023 Season

General rules:


     Rule a. replaced with: Bellhousing must be mounted as SFI certified by manufacturer with grade 8 studs or bolts that can be identified as grade 8. Socket head bolts allowed only for clearance problems.

     Rules e and f. replaced with: Bellhousing must be mounted with grade 8 studs or bolts per manufacturer’s bolt pattern for motor and bellhousing. All bolts must be in place.

     Rule i updated: Starting Jan 1, 2024 all SFI bellhousings regardless of material i.e. steel, titanium or aluminum must display a current SFI sticker with an expiration date affixed by the manufacture. The NTPA steel stamp will no longer be acceptable as a replacement for SFI decal after Jan 1, 2024.


     Exhaust rule 7, pg. 33 and 34 – added Or, a billet steel cross/cage incorporated into the exhaust outlet supplied by the turbocharger manufacture. (Dimensions still in process)

Injection Pumps

     P7100 Series Pump:  For classes limited to maximum size injection pump of P7100 series, pump housing (main pump body) dimensions not to exceed 2-5/8” wide X 9-9/16” long X 8-3/16” tall. Limit one plunger per cylinder. No billet pump housings.

     Divisions limited to P7100 injection pump are: Light Pro Stock, Limited Pro Stock, Pro Farm, Hot Farm, and Light Limited Super Stock.

     P8600 Series Pump:  For classes limited to maximum size injection pump of a P8600 series, pump housing (main pump body) dimensions not to exceed 3.175” wide X 10.475” long X 8.665” tall (+ or - .010”). Limit one plunger per cylinder. No billet pump housings. This rule will be included in Super Farm rules.

     Injection pump required to be mounted in the stock location only in affect for Light Pro Stock Tractors which is no change to previous class rules.

  Diesel Fuel

     All diesel fuel and diesel / bio blends will be measured using a dielectric meter only. A maximum reading of 13.4 / 150 based on which type of dielectric meter used.

Water Injection

    Water and soluable oil (lubricant) mixture must measure plus or minus .2 using a water hydrometer or a maximum reading of 5 on a refractometer.

Modified Tractors

     Light Unlimited deleted. Light Modified adopted and offered at SN/GN level.

Light Modified

     Limited to two supercharged automotive type piston engines limited to 14/71 size supercharger with no overdrive limit, or may be turbocharged. No single engine tractors, no naturally aspirated engines or turbines. Weight limit is 6,000 lbs.  

Mini Rod:

     Maximum weight will remain 2050 lbs. Vehicle no longer required to have any moveable weight.

Contest Operations

            “New” Sled Bump Rule

     a. Any competitor who breaks at the event site will receive hook points for all classes entered, but will not receive place points or any purse money unless there has been a measurable pull by that vehicle in that respective class except under circumstances covered in letter b.

      b. Competitor is not required to bump sled if breakage occurs during first session of competition and not able to compete in second session for same class only. Place points issued only in class with 15 or less total entries including per hook, non-member entries. Rule does not apply if vehicle has not competed in first session of class that breakage occurred. Vehicle must make a measureable hook in first session in order to qualify for last place points in second session of same class. If vehicle has already competed and recorded a measureable distance in a different class previous to breakage and is entered in that same class in a later session, then vehicle will be awarded place points under same conditions in both classes.
Example: vehicle competes in UNL in session 1 making a measureable distance and then breaks during competition in MOD class in session 2. If vehicle is unable to compete further in that event, then vehicle would qualify for last place points in second session for both classes under criteria described previous.

Contest Procedures

First Pull Attempt

     a. On first attempt, no matter where the vehicle stops prior to 100 foot, as long as competitor lets off the throttle prior to 100 ft. marker, no matter the circumstance causing (out of bounds, kill switch pulled, lost weight, roll over, etc.), competitor will get a second attempt. Even if vehicle travels beyond the 100 ft. marker, competitor will be allowed a second attempt as long as competitor let off the throttle prior to 100 ft. marker.

      b. If no attempt is made to let off the throttle, no second attempt will be granted.
      Note:  Intent is for driver not to slam on brakes to stop before 100 ft. marker (or at any time), but to come to a smooth, safe stop.

     c.  All competitors, except “Test Puller”, will have the option to make a second attempt immediately or drop (6) positions after first attempt as long as competitor did not go past 100 feet. Competitor will have one attempt remaining. For “Test Puller” options, see Section.......

Additional classes

Pro Stock Tractors – RN level on trial basis in Region 2

     Turbo limited to 5 inch intake and exhaust, no intercooler, all other rules for Pro Stock class in NTPA Rule Book remain the same as GN Heavy Pro Stock including cubic inch, component chassis and weight.

Super Stock FWD Trucks:

(this class will move from the back of the book to the front and be a regular RN class)

1. Super Stock FWD truck shall follow the NTPA Rulebook for Modified Four Wheel Drive except where superseded by rules found therein.

2. Maximum wheelbase of 133 inches for Super Stock FWD trucks. Must have OEM frame of a truck. All rear end housings must be fastened rigid to the frame. Front axle must be a Dana 70 or under automotive front.

3. Engine to remain in stock location as intended by manufacturer plus or minus 3 inches. Mini Truck (S-10, Ranger, Dakota, etc.) are permitted to run V-8 engines.

4. Front axle must remain in intended original location. Center of front or rear wheels cannot exceed plus or minus 2 inches of fender walls being used.

5. Engine must be the same manufacturer as the truck. Center to center bore spacing to be OEM stock on the engine (Ford 4.9, GM 4.84, and Mopar 4.8). Any cam allowed, and intake manifold changed permitted with one single, four-barrel carburetor with working floats and mechanical linkage. Not to exceed standard 4500 series dominator gasket. Engine must run on gasoline fuel only. Aluminum heads are permitted. No hemi or semi hemi style head. Heads must be cast and not billet. Fuel injection and/or air compressing devices are not permitted.

6. Engine block must be OEM stock steel or its replica, no aluminum engine blocks permitted.

7. Fuel samples and or fuel tests may be conducted at any time at the discretion of the competition director.

8. Hitches to be built to specifications in NTPA Modified FWD section. Hitch length to be a minimum of 30% of the wheelbase.

9. Maximum tire size is 35 inches tall by 12.5 inches wide or metric equivalent of 315/75. Must be a D.O.T. tire.

10. Can use aftermarket transmission and transfer case.

11. Any type of rear end may be used. (Military and or 2 ½ ton truck or automotive)

Note:   Region 2 is limited to 410 cubic inches

            Region 3 is limited to 530 cubic inches

            Region 6 is limited to 500 cubic inches

NTPA Rule Update: Effective immediately (this includes Shipshewana):

Page 28 of the 2022 NTPA rulebook “Shielding” #1 letter now reads:

J. All inline turbocharged engines are required to have a cable(s) placed between first and second cylinder through exhaust manifold port area. Cable must be a minimum of one (1) 3/8 manufactured pendant line with a rating of at least 3000 lb or more with a tag from the manufacture that indicates rated load capacity with swaged sockets.
Two (2) 3/8" cables with a minimum of 4 clamps at the splice or crimps with a coupler on each cable. Cable(s) must circle the entire head /block assembly with a maximum of 4" slack.

 Example of the pendant line and tag:

IMG 2010IMG 2011


 Tech Questions and Answers

  • Belhousing question


    Mr. Richwine, I bought a new Trick Titanium belhousing for my Mod FWD. I received it in January 2022. It has a current SFI sticker on it and all legal, but, it only has 13 bolts holes around the flange. It also has the 4 big quadrant holes. Do those holes count to meet the 15 bolts requirement? If not, do I need to drill two holes in it to be legal?  I see the rulebook states either 15 or 18 bolts around it to be SFI legal. Please tell me what to do.


     No, don’t drill any holes in it. If they sold it to you as a SFI certified belhousing with only 13 holes it’s legal. If you modify it by drilling extra holes in it won’t be re-certified when you have to send it to Trick Titanium for re-certification because you have modified it.

     Since the rulebook was printed this has come up a couple of times. The bottom line is NTPA wants you to have a “current SFI certified” belhousing properly installed on your vehicle starting January 1, 2023. If Trick Titanium sold you the can as “SFI certified” then NTPA will not tell you to modify it.



    Super Farm injection pump


    Richwine, what’s this I hear about the Scheid injection pump that I’ve been running in the Super Farm class for the past 5 years may not be legal?

    How the hell can that be true?


    The question was raised at Louisville as to the legality of a “P” pump that wasn’t a P7100 housing in the Super Farm class.

    The 2022 NTPA rulebook pg 62 under SF rules states that the pump must be a “P” pump but, doesn’t specify that it has to be “7100 series”.

    After research, review and consideration the NTPA exe board has decided that this issue should be reviewed in September of 2022 by the SF division and better clarified at that meeting for the 2023 rulebook.

    So, the Scheid pump you’ve been running can continue to run for 2022.

    Crossbolts in turbo exhaust


    Richwine, I was told at Shipshawanna that the rules had changed and I had to have 1/2 “ bolts instead of 3/8” bolts as close to the exhaust wheel as possible, Is that true?


    Yes, the rule changed two years ago. You have to have 2  - 1/2 “ bolts in the horizontal part of the pipe as close to the exhaust wheel as possible.  Also, the turbos that have a cross in the turbo exhaust housing from the manufacture doesn’t count. The exhaust pipe still has to have the cross bolts (1/2”) in the horizontal part of the pipe.

    Bio Diesel


    Mr. Richwine

    Is BioDiesel legal for NTPA competition in 2022?  I see where you raised the dielectric reading to 150 but I thought that would eliminate B100. Is this not true? There seems to be a debate if Bio is legal or not.


    We did raise the dielectric limit to 150 for diesel fuel, but, the rules for BioDiesel did not change. The B100 rules are exactly the same as they have been in the past. So, yes biodiesel is still legal.



    Mr. Richwine, my partner and I are coming to Ocala and run the LLSS class. What all do I have to do to pass inspection? We run about all the different groups here in New England, but, we’ve never ran at a NTPA event.


    The NTPA rules for all classes will apply to all of the classes that are scheduled at Ocala. This includes all safety rules like inner side shields, cross bolts in the turbo exhaust pipes, rollcage and attachment, firesuit and equipment, etc. Better get there early and get checked ASAP.

    Reverse light question


    Larry I’m getting close to ready to loading and headed Fl.  I’ve been hearing people needing a neutral light on back of tractor ???  Is this a new rule?? A neutral light and neutral safety switch??? Not sure how power it with safety switch being ground. If it needed.  Sending memberships in next week  so I don’t have new rule book thanks

    NTPA requires a 2 inch white light on the rear of the vehicle to indicate “reverse” as well as a “neutral” switch to keep it from starting in gear.
    The other group requires amber light for neutral.

    Belhousing bolt question

    Mr. Richwine, I was told I can’t use hex socket head bolts to attach my belhousing to my engine / block plate. Is this true?  Some of the bolt holes are so close to the bell that a normal hex head bolt can’t be used. What the heck should I do?

    I understand that this is a problem on some belhousings, so, in this case, you will be allowed to use a hardened hex socket head bolt as long as all the other fasteners are grade 8 bolts and / or studs.

    New Bellhousing rules


    Hey Richwine, what’s this BS that I’ve gota get my steel Lakewood belhousing inspected by Lakewood and have a sticker on it? You guys stamped it so I didn’t have to worry about the sticker or if it was current.


    Yes, Starting Jan 1, 2023 all SFI belhousings regardless of material i.e. steel, titanium or aluminum must display a current SFI sticker with a expiration date affixed by the manufacture. The NTPA steel stamp will no longer be acceptable as a replacement for SFI decal after Jan 1, 2023.

    Mini Rod question


    Hey Richwine, Did the Mini Rod trans mounting rules change after Bowling Green?


    No, nothing changed yet. The number of bolts may change for 2022 but, we will finish the 2021 season same as in the past.

    Pulloffs at Bowling Green


    Mr. Richwine,


    Will there be pulloffs at BG this year? I've noticed that you havent had pulloffs at any events this season.


    Yes, there will be pulloffs if they go past 350 feet. The NTPA rulebook allows for a max distance of 350' I realize we've exceeded that distance at several events but there's not really enough "runoff" room past 350 here at Bowling Green to allow it. The pullers will be red flagged if they go past 350 and will be required to come back for a pulloff. 

    Turbo Blanket


    Can I run if I don’t have a turbo blanket but have it ordered?
    Also, can I build a steel shield around my compressor housing instead of buying a blanket?


    No, you are required to have a Kevlar blanket around you “high pressure” or last turbocharger’s compressor housing in a multi turbo setup. 

    Also No, a steel cover instead of a blanket will not contain the fragments as well as a properly installed blanket.

    If you show up at a NTPA event without a blanket you will have to borrow one or just not pull.

    Note: A turbo blanket is only required in classes that allow a turbo inlet larger than 3 inches.

    Turbo measurement


    Mr. Richwine, I’m new to NTPA, how do you guys measure the turbo? I say that the wheel where it sticks thru the housing should be 3” and everybody tells me I wrong it’s the housing.


    Sorry, they're correct and you’re wrong. When NTPA first started measuring the Super Farm class and actually made them tear the turbo down to be measured and sealed  we set the president of measuring the bore of the housing at the face of the wheel like the rules state.

    We measure several different classes now and they’re all measured the same way. We use a slug or a  “Go /No Go” gauge. Sounds like if measured at a NTPA event that your turbo will not pass.

    Light Limited SS


    Mr. Richwine,

    Are the LLSS rules set in stone? What about the WTPA tractors that don't fit the rules you published? Are you gona allow front suspension?


    The rules that are posted are final and in place for 2021. I suggest that any changes you or any group wish to make be subbmitted for the September meetings of 2021. If they are adopted, they would be in effect for the 2022 season.

    Diesel Fuel rule for 2021


    Hey Mr. Larry,

    Did the NTPA raise their diesel fuel spec like the other guys did?


    No, its still at a max number of 100 for 2021.

    Cables around the engine


    Mr. Richwine, My engine builder wants me to run 3-4 cables around my engine after the Light Pro explosion at a non sanctioned event this summer, can I do that?


    No, only one cable is required or allowed around in line engines in NTPA competition. I understand your engine builders concern but, years ago when the cables were first required we required two cables. We found that only contained the explosion enough to make smaller pieces fly. The cables job is to flip the assembly away from the driver. Everyone always says "but the cable broke" and thats true, but, before it breakes or pulls out of it clamps it does the job as intended.

    If you come to a NTPA event with more than one cable on your engine you will be told to take all the extra ones off before you're allowed to run unless you have a Moline or case, then they require a cable for each head.


    Super Tech


    Richwine are you doing "Super Tech" at Ft Recovery?


    Yes on Saturday from 11am - 2PM on Mini Rods and Unlimited only

    Water test


    Hey Richwine, I hear that the Super Farm pullers had trouble in Rockwell passing the new water test you have. Is that true? what the heck are you doing?


    NTPA does have a new test but, it's no different that PPL's, so if your water will pass there, it will pass here.


    MSD 600 CDI



    Is the MSD 600 CDI unit legal on my mini rod for NTPA competition?


    The Msd 600 cdi by definition of the timing control rule is a legal component when used as only an energy provider for individual coil packs. It only becomes illegal if an external controller is used in conjunction with the 600 cdi in order to adjust ignition timing during a competition run.

    Rain out rules


    Mr. Richwine,

    Please explain how a “Rain Out” works. When can the promoter call it off where I don’t have to show up to get rain points etc. I’ve heard a bunch of different versions of what should or has happened.


    Page 88 of the 2019 NTPA rulebook under letter E Inclement Weather states:

    #7. If a session is cancelled more than 24 hours prior to start time
    at GN/SN or 8 hours at RN/PN/state level, no points will be given
    for that session.
    #8. If a session is cancelled prior to start time, competitors will
    receive refund of paid entry fees, but no other compensation.

    With that said, if the event isn’t canceled within the time period described in #7 then you do have to travel to the event with your pulling vehicle and check in so the entry personnel can record your entry in order to receive rain points. The entry trailer must remain open until scheduled start time of the event in order for you to “check in”.

    As to “Why do I have to take my pulling vehicle with me?” page 81 under Event Procedures and Requirements #4 reads:

    #4. Vehicle must be present on the ground in running order and
    ready to compete before being allowed to enter.

    Light Pro/Limited Pro Stock Turbo



    When the rule says exhaust limit 4.5 inch and the wheel must proturde .125 inch into the bore, will the nut count? Its part of the wheel. Or if I have a couple of little fins in front of the regular wheel will they count? 

    No, the nut doesnt count. The rule says

    1. Turbo limited to 4.5 inch diameter exhaust to be measured at the face of the wheel.
    2. Exhaust wheel tips of wheel (each blade/fin, nut does not count) must protrude into the 4.5 inch bore by 0.125” minimum.
    3. All exhaust must exit the 4.5 inch bore.
      We are going to measure the turbo just like we have on the Super Farm class's 3 inch bore since the days when we "sealed" the turbo with a lead seal.

    If we question how deep it goes into the bore you will be required to disassemble your turbo so we can measure it.

    I included a picture of how / where we will measure the wheel

    turbo exhaust

    Hot Farm tires


    Mr. Larry,
    Can I run my 24.5 tires in the Hot Farm class? I dont want to buy 20.8's but, my tractor fits the hot farm class all but tires.
    If not, WHY not.


    No, you can't run the 24.5 tires in the Hot farm class. The reason is that the class needs to and does look different than all the other classes from the grandstand.
    You will be surprised how good your tractor hooks up with 20.8 tires on it.

    Expired Roll Cage Sticker

    Can I run my tractor with an expired roll cage sticker?
    Yes as long as the old sticker is still in place. The Techs know (becuase they have been told in tech school) that you can run until you find one of the roll cage inspectors.

    Hitch Question


    Mr. Richwine,

    What’s the deal with the new “V” hitch I’ve heard about for Mini rods? Are they legal? Are they gona be allowed in all classes? Asking for a friend.


    No, they aren’t legal the rulebook states in general rules as well as some class rules that nothing can obstruct the chain or the hooking or unhooking of it. The “V” cut design not only would cause difficulty in hooking (if not straight with the sled) but would also make unhooking harder than it already is. Also, when the hook tries to go from side to side when the vehicle gets sideways it will affect the angle of the hook and change the draft of the chain.

    The cross sectional thickness of the point of hook is also spelled out in the rulebook for all classes. This too can affect the hook and the draft of the chain.
    Drawbar Design

    Tech School


    Mr. Richwine,
    Can anyone attend the tech school or do you have to be one of the "Click" to attend??


    The school is open for anyone to set in on but, in order to take the test and become a NTPA licensed official you must be endorsed by either a NTPA member state or by the NTPA itself.

    New SF turbo 3"charger


    Mr. Richwine,

    I hear that Hart has a new 3" charger that measures a fuzz over 3 inches.It was allowed to run last weekend in NC at a non NTPA event. Will that be allowed to run at a UPOC event? If so what's the limit?


    I heard about the new turbo and have had a couple of calls already. I can assure you that NTPA won't allow that and if they are found to be on a tractor at a NTPA event, they won't be allowed to run or if they are found to have run after the fact the tractor will be DQ'd.As luck would have it, I will be at Pinetops and Benson and will make sure the SF chargers are checked.

    Mounting OEM Rollcage


    Hey Richwine,
    I’m new to NTPA and I can’t find the rollcage mounting spec anywhere in the rulebook. I have a D-21 and need to mount an AccuFeed cage to it. Where is it and what do I need to do?


    The Rollcage spec is a SFI 47.1, that’s all that’s listed in the book. The mounting to a OEM chassis is as follows:

    Mounting must use at least 3 axle housing bolts on each side as well as 1 bolt before and after the axle housing. There bolts must be in sheer (horizontal ) with a total of 2 9/16” bolt material. 
    mounting cage

    Rollcage Webbing

    Mr. Richwine,

    I am building a Mini Rod and have a question about the webbing between the upright tubes? Can they be lightened? If so, how much? I have included a photo of the chassis that is available and they look like they have been lightened a lot.

    Yes the shear webbing that goes between the up tubes can be lightened by 40%.
    The Spec says: shear web may have lightening holes but must retain 60% material and must have a minimum of 1 inch around the perimeter of the web on all four sides. This applies to both Mini Rods and Big Tractor rollcages.
    After looking at the photo you are correct this will not pass the SFI / NTPA inspection and will have to be corrected before they are allowed to compete with NTPA.

    Rollcage Inspection Cost


    Mr. Richwine,
    I'm not a member of NTPA but, would like to run at the upcoming event. I need to get my cage inspected, is there a charge for that?

    Here's the program that's been in place since 1999 when the cage was implemented.
    All vehicles that compete at a NTPA event must have the rollcage inspected and display a NTPA/SFI certification sticker or the vehicle will not be allowed to hook.

    1. Upon passing inspection and paying the fee of $75.00 per cage to NTPA on vehicles that have a paid NTPA membership. The rollcage will have a certification sticker applied to it that denotes the inspection date, it will be valid for a period of five (5) years before being required to have their rollcage reinspected. Unless an accident occurs that involves the rollcage.
    2. A service fee of $100.00 will be added to a cage that is on a non NTPA member vehicle. This $100.00 fee will be applied to a regular membership (not per hook) if the vehicle joins NTPA within a 60 day period from the date of inspection.

Contact Info

National Tractor Pullers Association
6155-B Huntley Road,
Columbus, OH 43229

PHONE: (614) 436-1761

FAX: (614) 436-0964